Wrench



April 30, 1946.. F A SNELL 2,3@9fi5% WRENCH Filed Dec. 9, 1944 I INVENTOR.

I rancid a. JMZZ/ BY A coil spring 28 surrounds the adjustment screw M and has one end operative against the inside face of the rear wall 4 of the frame I, and has its other end bearing against the movable jaw l8, the spring thus serving to maintain the head l6 of the adjustment screw l4 against the rear wall of the frame and keeping the spherical part of the screw against its seat l1.

It will be observed that the link 25; the engagement of the pin 9 with the arcuate slots 8, and the shape and disposition of the actuating handle and its connection with the parts, forms a toggle linkage system so arranged that when the actuating handle 23 is moved toward the handle part 5, the movable jaw assumes a parallel relationship to the stationary jaw 6, the respective gripping surfaces 1 and of the two jaws being parallel, as clearly seen in Fig. 1, and a clamping action is effected when the link passes beyond its dead-center position to lock the parts in clamping engagement with an object located between the jaws. This effect is secured each time that the actuating handle 23 is moved to closed position, or to the position shown in Fig. l, regardless of the position to which the movable jaw l8 has been adjusted by means of the adjustment screw Id. In other words, the wrench may at any time be adjusted to closely fit any size nut or other object within the range of normal operation according to the size of its parts, by turning the adjustment screw I4 to move the pin 9 in the slots 8 for the required extent to position the movable jaw [8 at the desired distance from the stationary jaw 6. Once that this adjustment has been secured, it can only be altered by further manipulation of the adjustment screw M, for while the outward movement of the actuating handle 23 will swing the movable jaw 13 on its pivot 9 to cause said movable jaw to swing angularly away from the stationary jaw, as shown in Fig. 2, and thus free the object gripped between the jaws, a return movement of the actuating lever 23 will not only restore the gripping surface 26 of the jaw I8 to parallelism with the surface 7 on the stationary jaw, but it will position it at the same distance from the stationary jaw at which it was located before being moved to open position. 7

It is to be noted that the arcuate slots 8 are each cut as an arc of a circle having a radius equal to the length of the toggle, that is to say, equal to the distance between the centers of the pivots 22 and 21 when the device is in closed position, so that co-operation of these slots with the linkage arrangement shown and described produces the results herein set forth.

It will thus be apparent that when the wrench is once set for a particular size of object, it can be instantly released from engagement with the object by merely swinging the actuating handle away from the fixed handle part 5. At the same time, each return movement of the actuating handle will enable the wrench to grasp the object or any other similarly sized object.

Having described one embodiment of the invention, it is obvious that the same is not to be restricted thereto but is broad enough to cover all structures coming within the scope of the annexed claims.

What I claim is:

1. A tool of the character described comprising, a frame provided with a stationary jaw having a pair of spaced walls, said walls being each provided with a curved slot, a pin extending transversely of the stationary jaw and provided with end portions mounted for slidable movement in the slots to thereby bring the pin to or from the stationary jaw, an adjustable and pivotal jaw pivotally mounted on said pin between the walls of the stationary jaw, the frame having an aperture between the walls, an adjustment screw axially movable through said aperture, the pin having an internally threaded opening, the adjustment screw threadably engaging said opening, a coil spring surrounding the adjustment screw and having one end operative against the adjustable jaw and its other end bearing against the frame, an actuating handle pivotally connected to the adjustable jaw, and a link pivotally secured at one of its ends to the handle and at its other end to the frame.

2. A tool of the character described comprising, a frame provided with a stationary jaw including a channel-shaped part having spaced side walls integrally united by a back wall, each of the side walls having a similar curved slot, the longitudinal axis of which is substantially at right angles to the gripping face of the jaw, a movable jaw pivotally and adjustably mounted between the side walls of the stationary jaw, a pivot pin on which the movable jaw is pivotally mounted, said pin being movable in the slots, an adjustment screw threaded through the pivot pin, the back wall portion of the frame having a passage for the adjustment screw, a curved seat on the frame surrounding the passage, the adjustment screw having a portion complementary to said seat and maintained against the same, a spring operative to hold the adjustment screw against the seat, the spring being disposed between the movable jaw and the back wall of the frame, an actuating handle pivotally connected to the movable jaw, and a link pivotally secured at one of its ends to the handle and at its other end to the frame.

3. A tool of the character described comprising, a frame having a stationary jaw provided with a gripping surface, an adjustable and pivotally mounted jaw, the frame being provided with curved slots to guide the adjustable jaw, a pivot pin provided with an internally threaded aperture extending transversely of its axis, the adjustable jaw being pivotally mount-ed on said pivot pin, the pin having trunnions extending into the slots, the frame having an aperture, an adjustment screw extending through said aperture and having a spherical bearing portion operative against the frame around said aperture, said adjustment screw threadably engaging the threaded aperture in the pivot pin, spring means for maintaining the head of the adjustment screw in contact with the frame, a toggle connection between the adjustable jaw and the frame, said toggle connection including an actuating handle and a link pivoted thereto at one end and pivoted at its other end to the frame whereby the adjustable jaw has its gripping face disposed parallel to that of the stationary jaw when the toggle is in closed position, the slots being arcuate.

FRANCIS A. SNELL. 

